Abstract: A pneumatic percussive device has a casing (1) accomodating a movable hammer piston dividing the interior space of the casing (1) into two chambers. One of these chambers (7) alternately communicates, by means of an air distribution arrangement (3) having a movable actuator member (8), with a compressed air source and with the environment. In addition, said chamber (7) communicates, via a throttling passage (27), with a cavity (10) of the air distribution arrangement (3) the pressure in which ensures movement of the actuator member to one of its limit positions.

Abstract: An air-operated reversible percussive action machine comprises a housing (1) accommodating a reciprocating hammer (2). Secured inside the housing (1) is a stepped tube (5). The step of larger diameter of the tube (5) is received by a cavity (4) of the hammer (2) and has a port (12) for distributing air flow and feeding it to the interior of the housing (1). The tube (5) receives a sleeve (14) having a port (15) alternately communicable with the port (12) of the tube (5) in one of its two positions. One end face of the tube (5) has a projection (13) in the form of a sector of a circle, whereas the sleeve (14) is provided with a radial projection (16) so that in turning the sleeve (14) its projection (16) bears on one of the side walls of the projection (13) of the sleeve (5) thus assuming one of the two positions.

Abstract: A reversible air-operated percussive action machine for driving holes in the ground has a housing accommodating a hammer 2 capable of reciprocating therein. An air distributor 3 is arranged in the hammer 2 in the form of a fixed tube 12 and a valving member 13 movable relative to the tube. Defined between the tube 12 and valviong member 13 is an accumulating chamber 18 which communicates with an air feeding line 4. An air restrictor is further provided for discharging air from the accumulating chamber 18 when the supply of compressed air to the air feeding line is terminated. The valving member 13 spring-loaded relative to the tube 12 by a spring arranged so that during feeding compressed air to the accumulating chamber 18 the valving member 13 is acted upon by a pressure force directed counter to the action of the spring.

Abstract: A percussive tool comprises a percussion mechanism and a pressure pulser. The percussion mechanism has a hollow housing with a piston hammer arranged thereinside to form two chambers of variable volume. The pressure pulser has a hollow housing and a fluid displacer defining inside the housing a working chamber adapted to alternately communicate with a source of gaseous fluid and the interior of the percussion mechanism. The fluid displacer is intended for forced displacement inside the housing to transmit to the chambers of the percussion mechanism a pulsed pressure of the gaseous fluid which causes the piston hammer to reciprocate. The interior of the percussion mechanism is isolated from the outside, whereas the working chamber of the pressure pulser communicates with at least one of the chambers of the percussion mechanism, the chambers of the percussion mechanism continuously intercommunicating by way of a restrictor passage.

Abstract: A pneumatic percussive tool has a barrel in which is inserted a hammer piston imparting blows at a working tool at regular intervals. A floating sleeve surrounding the working tool is provided in the front end portion of the barrel, the sleeve having a projection defining with a barrel groove a damping chamber communicating with a source of compressed gas. There is provided a shell rigidly secured to the barrel, which surrounds the sleeve so as to define in the zone of its projection an auxiliary damping chamber communicating with the source of compressed gas when the sleeve is in its lower position.

Abstract: A rock-breaking tool for preferable use in self-propelled percussive machines for boring wells, comprising a casing with a pointed portion and an end face. The casing has an annular cutting edge formed by the pointed portion and inner tapered surface thereof. The casing is formed with a cone-shaped chamber open at the end face thereof, oriented toward the bottom of a well being drilled, the internal surface of the chamber intersecting with the conical surface of the annular cutting edge. The casing is also provided with ducts communicating the chamber with the surrounding space.

Abstract: A percussive device operable in a forward mode for making a hole in soil and operable in a reverse mode to retract the device from the hole. The device is provided with control means that change the mode of operation alternatively under control of a valve that turns air pressure on and off in a supply or feed line to the device. When the air is turned off from the device the valve establishes connection to an aspirator for establishing a suction condition to the device that will reverse the mode so that upon turning on of air back to the device will make it operate in the changed-over mode.

Abstract: The device comprises a hollow cylindrical body, pointed front at its end which device accommodates a striker forming the front working chamber in said body, and has a cylindrical space at its rear end. Said space receives an air-distributing and reversing mechanism, thus forming the rear working chamber. The air-distributing and reversing mechanism has a bushing which is fixed relative to the body, and an axially movable bushing, both bushings being arranged coaxially, spring-loaded in the axial direction relative to each other, and forming a chamber located in the front part of said mechanism, with the chamber communicating with a source of compressed air and intended to move the movable bushing during reversal of the device.